Jeff Janes <jeff.janes@xxxxxxxxx> writes: > On 7/12/11, lars <lhofhansl@xxxxxxxxx> wrote: >> The fact that a select (maybe a big analytical query we'll run) touching >> many rows will update the WAL and wait >> (apparently) for that IO to complete is making a fully cached database >> far less useful. >> I just artificially created this scenario. > I can't think of any reason that that WAL would have to be flushed > synchronously. Maybe he's running low on shared_buffers? We would have to flush WAL before writing a dirty buffer out, so maybe excessive pressure on available buffers is part of the issue here. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
